On my '71 Supreme (w/350 4bbl, auto), when I depress the accelerator pedal once to set the choke, the butterflies are closed, no gap whats so ever, shouldn't I have about a 1/8" opening? This carb was recently rebuilt by a known builder, so I'm a bit miffed by this, as it is now resulting in hard starting (runs fine otherwise). How do set this to get the correct gap? Thought that I had a Rochester book, but cannot find it. Any help would be appreiciated.

 

When you depress the accelerator to set the choke, the butterflies close. When the engine starts, the choke pull-off opens the plate slightly.

The amount of pull-off can be adjusted, as can the initial choke tension.

 

I'm having a problem of hard starting, a lot of cranking, and difficult to fire up. This started about a month ago. I hit the throttle once to set the choke, and it proceeds to crank quite a bit before firing up, I am reluctant to pump the gas as I do not want to flood it. Took it out today cranked about 5 seconds and fired up, stopped and got gas, and it restarted no problem, though the last time that I drove it two weeks ago it was a pain to start. Drove it 15 miles today, shut it off for about an hour, and it restarted fine but shuddered a bit @ idle.

 

Well, I started it up today no problem, backed it out of the garage for better lighting and took a look at the dist. cap and points. There was corrosion on the rotor contact in the center, which I sanded off, along with where it contacts at each terminal. Points were pitted, so I replaced them (Accel), buttoned it back up..and...no start! cranked and cranked, could smell gas, but would not start. I am letting it sit awhile before trying again. I plan on buying a new cap and rotor tommorow. But, I am still baffled.

 

One word: Edelbrock

 

Two words...no.

 

I thought "no" was one word.

 

Yep, right after I hit "post reply" I caught it, brain fade. I'm now convinced that it is electrical, as it is getting gas, but cranks forever. Had to push it back into the garage. Strange that it would go from starting and running fine to this, I'm baffled. I will check the coil for spark, and if good, a plug wire at the plug for an arc. I work second shift, so it is impossible to get a helper to crank it while I observe to see if it is arcing.

 

Just a thought here but a lot of times NEW point sets need to have the breaker contact 'scuffed' before they work correctly. Something about the 'flash' finish they put on the new set impedes a good arc and needs to be 'scuffed' lightly with a fine abrasive sandpaper just enough to take the 'finish' off.

 

I'll give it a try...couldn't hurt.

 

the "finish" you mention is actually oxidation. points oxidize from sitting unused, new or used. a very fine contact file is all you need, or, some 2000 sandpaper. put it in between and pull it out while the points are closed with the key off. do this once for each contact on the set of points. i have found that a plain piece of paper will work too, though it may take a few more "swipes" with plain paper.

hei upgrades solve this problem.


bill

 

I can get the Accel unit locally for 85 bucks, and have been considering Pertronix for awhile, but I do not want to make the upgrade until I find out what the problem is.

 

Change the condensor also, no sense leaving the old one in, they do fail.

 

I have done the following: replaced points, condensor, rotor, dist. cap. and the coil. I have no idea what it could be, if it had stopped running while driving down the road, and then cranked and failed to restart, I would suspect the timing set. I am at my wits end with this, never had it happen before in years gone by, so I really cannot pin point.